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RELATIONSHIP AMONG
ROOT CHARACTERISTICS AND DIFFERENTIAL POTASSIUM UPTAKE AND USE
EFFICIENCY OF SELECTED COTTON GENOTYPES UNDER
POTASSIUM DEFICIENCY STRESS
ZIA-UL-HASSAN1*
AND MUHAMMAD ARSHAD2
Abstract:
Potassium
(K) uptake and K use efficiency are the most important characters of
plant genotypes that determine their biomass production under K
deficiency stress. This study reports the influence of some important
root characters on the K uptake and use efficiency of three pre-selected
cotton genotypes under K deficiency stress. These genotypes included
CIM-506, NIAB-78 and NIBGE-2, selected on the basis of their
differential K use efficiency i.e., low, medium and high, respectively.
Cotton genotypes significantly (p<0.01) differed for their K use
efficiency, K uptake of shoot, root and on total basis, tap-root length,
lateral root number and specific K absorption rate based on tap root
length. While, K accumulation rate, K translocation efficiency, K
transport rate and specific K absorption rate based on root dry weight
were non-significant. The genotype NIBGE-2 was the most tolerant
genotype to K deficiency stress and performed best for all the
parameters studied followed by NIAB-78 and CIM-506. A significant
correlation was observed between K use efficiency and K uptake of cotton
genotypes. The root characteristics viz., tap root length, lateral root
number, K accumulation rate and specific K absorption rate directly
influence both K uptake and use efficiency of cotton under deficient K
condition. K translocation rate and specific K absorption rate, based on
root dry weight, directly influence total K uptake but not K use
efficiency. These physio-morphological root traits of cotton are highly
important while breeding for K-use-efficient cotton genotypes.
1Sindh
Agriculture University, Tandojam, Pakistan,
2University
of Agriculture, Faisalabad, Pakistan
*E-mail:
zhnshah@gmail.com
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